The gastrointestinal tract provides a protective interface between the internal environment and the constant challenge from food-derived antigens and from microorganisms in the external environment (Sanderson et al., 1993). The complex ecosystem of the adult intestinal microflora is estimated to harbor 500 different bacterial species. Some of these species are considered potentially harmful because of toxin production, mucosal invasion; or activation of carcinogens and inflammatory responses (Salminen, 1998). However, bacterial strains with health promoting activities have been identified.
Probiotics are beneficial bacteria that exist in the healthy gut microflora and have been defined as a group of live microbial organisms which beneficially affects a host animal by improving its intestinal microbial balance. They consist of “friendly bacteria” which are cultured in laboratory conditions and are then used to restore the balance of the microflora, which has become unbalanced because of, for example stress, illness, or as a result of the use of antibiotics. Importantly, it has been shown that the ingestion of probiotic bacteria can potentially stabilise the immunologic barrier in the gut mucosa by reducing the generation of local proinflammatory cytokines (Isolauri, 1993; Majamaa, 1997). Alteration of the properties of the indigenous microflora by probiotic therapy was shown to reverse some immunologic disturbances characteristic of Crohn's disease (Malin, 1996), food allergy (Majamaa, 1997), and atopic eczema (Isolauri, 2000).
One of the predominant bacterial species present in the intestinal microflora is Bifidobacterium. In the intestines, Bifidobacterium ferments sugars to produce lactic acid. The Bifidobacterium longum genome codes for many proteins specialised for the catabolism of oligosaccharides, enabling the bacterium to use so-called “nondigestible” plant polymers or host-derived glycoproteins and glycoconjugates. It is thought that Bifidobacterium's ability to compete with other gastrointestinal bacteria and occupy a large percentage in the bacterial flora of the gastrointestinal region might be partly due to the large variety of molecules that it is able to use for energy.
While B. infantis, B. breve, and B. longum are the largest bacteria group in the intestines of infants, Bifidobacteria are said to be only the 3rd or 4th largest group of bacteria in adults (and only 3-6% of adult fecal flora). The number of these bacteria actually decline in the human body with age. In infants who are breast-fed, Bifidobacteria constitute about 90% of their intestinal bacteria; however, this number is lower in bottle-fed infants. When breast-fed infants' diets are changed to cows milk and solid food, Bifidobacteria are joined by rising numbers of other bacteria found in the human body such as Bacteroides and Streptococci lactobacilli. 
Bifidobacteria have been shown to play a role in the modulation of the immune system. B. breve is thought to release metabolites exerting an anti-TNF effect capable of crossing the intestinal barrier. Mucosal inflammation in interlukin-10 (IL-10) deficient mice has been reported to be reduced by feeding the subject animals a preparation of lactic acid bacteria (Madsen, K et al., 1997; O'Mahony et al., 2001; McCarthy et al., 2004). W0 00/41168 discloses a strain of Bifidobacterium infantis isolated from resected and washed human gastrointestinal tract which is significantly immunomodulatory following oral consumption in humans.
Scientific research indicates an increasing incidence of illness which may be caused by deficient or compromised microflora (natural microbial resident population of the digestive system) such as gastrointestinal tract (GIT) infections, constipation, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis, food allergies, antibiotic-induced diarrhoea, cardiovascular disease and certain cancers such as colorectal cancer. Evidence indicates that following treatment with a single Bifidobacterium infantis strain, IBS symptom severity is reduced (Whorwell et al., 2006). Efficacy is associated with modulation of systemic immune responses indicating that the mechanism of action, in part, is immune mediated (O'Mahony et al., 2005). The present invention describes a compound isolated from Bifidobacterium infantis that replicates the immunomodulatory activity of Bifidobacterium infantis in vitro.